The Chemical Industry: risks and rewards

1
The Chemical Industry risks and rewards

• Chapter 18

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Australias chemical industry

• Read page 296 The beginnings of an industry
• Australia is about 20th on the list of world
  exporters of chemicals, with annual trade worth
  around US3 billioin.
• Over 40 000 Australians are employed directly in
  the industry.
• Overall about 1 person in 10 are employed in a
  job either directly or indirectly related to the
  chemical industry

3
Industrial chemists

• A range of different skills and qualifications
  are required by industrial chemists.
• Chemical engineers constantly supervise the
  operation of the plant, solve production
  problems, develop modifications to the existing
  plant and assist in the design of new projects.
• Analytical chemists are concerned with quality
  control, providing analysis of raw materials,
  products and emissions and problems, develop
  modifications to the existing plant.
• Research chemists undertake research on new
  processes and new materials and develop new
  analytical techniques

4
Yields

• The extent of conversion of raw materials to
  product is influenced by reaction conditions such
  as temperature, pressure and concentration.
• To avoid waste and reduce costs, conditions are
  carefully selected to ensure that acceptable
  yields of product are obtained.

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Yields

• Chemists therefore try to ensure that
• The reaction rate is fast
• A high proportion of reactants is converted to
  products at equilibrium
• Turn to table 18.1 on page 299
• There is often a need to compromise between rate
  and equilibrium considerations.

6
Batch processing

• Is one of the two main ways that reactions are
  controlled in industry.
• It is the method used when fixed amounts of
  reactants are mixed, giving fixed amount of
  products.
• It is used when there are low costs or negligible
  delays in starting or stopping productions, for
  one-off productions and small quantities of
  product.

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Continuous flow processing

• Reactants are mixed continuously, providing a
  constant supply of product.
• This technique uses smaller, less expensive
  equipment than batch processing.
• Is the preferred method when there are high costs
  or long delays in starting or stopping
  production.
• It allows greater control over reaction
  conditions, especially temperature, than batch
  processing.

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Costs

• Other factors that influence the final choice of
  reaction conditions.
• Catalyst a less expensive one may be preferred
  to a more efficient one
• Pressure high-pressure reaction vessels are
  costly to build and operate
• Temperature fuel costs rise rapidly as
  operating temperatures increase
• Choice of reactant to use in excess
• Safety and waste minimisation and disposal. The
  safest option is not always the cheapest
• Energy costs

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Your Turn

• Page 301
• Question 3, 4 and 7

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Occupational Health and Safely

• This is the area of employee safety.
• Australia has laws that enforce a duty of care by
  organisations that supply or use chemicals.
• Penalties for negligence that results in
  someones death or serious injury can include
  hefty fines or imprisonment.

11
Dangerous Goods and Hazardous Substances

• Dangerous goods have the potential to pose
  immediate danger to people, property or the
  environment.
• Examples of dangerous goods include
• Petrol
• Pool chlorine
• Ammonium nitrate fertiliser.
• Turn to page 302 for the HAZCHEM signs

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Dangerous Goods and Hazardous Substances

• Hazardous substances are classified on the basis
  of their short- and long-term effects on the
  health or safety of people.
• Some such as a asbestos may cause illness or
  disease some time after exposure.
• Over 2000 Australians die each year as a result
  of exposure to hazardous substances.
• Warning signs about dangerous goods are required
  at any site where they are used or stored.

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Risk Assessments

• A risk assessment is a formal way of identifying
  risks and assessing potential harm from a
  hazardous chemical in a particular situation.
• Effective risk management reduces exposure to
  hazardous chemicals to at least acceptable
  levels.
• Victorias OHS regulations require schools to
  perform a risk assessment for each activity using
  hazardous chemicals

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Risk Assessments

• Risk assessments should include
• Identification of hazardous chemicals (products
  as well as reactants)
• Assessment of the risk
• Control of the risk (how do we minimise the risk
  and disposal)
• documentation

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Material Safety Data Sheets

• Manufacturers have to supply MSDS for hazardous
  substances.
• An MSDS needs to provide
• Company name and contact details
• Scientific and trade names
• Major uses and applications
• Physical data (appearance, colour, boiling point,
  solubility etc)
• Health effects
• Treatments
• Precautions
• Safe handling
• Date of publication

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Your Turn

• Page 306
• Question 9

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Waste Management and Pollution

• A waste is considered as an unwanted or unvalued
  substance that is discarded or discharged.
• Wastes occur as
• Contaminated soil and solids
• Organic liquids of low volatility
• Wastes containing high volatile liquids
• Solid and semi-soli process materials
• Aqueous wastes
• Sludges, spillages
• Products past their used-by date
• Hazardous waste may be toxic, radioactive or
  contaminated by disease-causing organisms

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Chemical waste is generated form many sources
19
Some effects are long term!!
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Waste Treatment

• Industrial waste treatment technologies now go
  beyond landfill and dumping at sea.
• They include high-temperature incineration and
  vitrification.
• Other options still under development include
• Dispersion in controlled amounts in water or air
• Removal of pollutants from waste gases and liquid
• Storage in sealed drums in secure locations
• Catalysed dechlorination
• Ionic replacement of halogens in halogenated
  organic compounds
• High-temperature steam and water treatments

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Waste Treatment

• Chemical industries aim to deal with wastes in
  the following strategic order of priority
• Prevention
• Elimination
• Reduction
• Recycling
• Treatment
• Disposal

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Green Chemistry
23
Your Turn

• Page 310
• Question 12, 14 and 17

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Location of a plant

• What kinds of things would you need to consider
  when deciding on a location for a chemistry
  plant???